1. Field of the Invention
The invention relates to display control circuits, particularly circuits used in CRT displays, or the like.
2. Prior Art
In numerous applications such as in the testing of a variety of electrical systems, it is necessary to display a signal for visual examination or to measure characteristics of the signal on a calibrated display. For example, the signal under test (hereinafter referred to as the "test signal") may be examined to determine its rise time, decay time, width, amplitude, harmonic content or other characteristics on a cathode ray tube (CRT) or other display.
In many such testing applications a trigger pulse is generated and applied to the tester (which includes the display) prior to the time that the test signal is received by the tester. However, the period between the trigger pulse and test signal is often unknown. To display such a test signal manual switching and adjusting are required.
As will be seen, the present invention provides a system for automatically displaying a test signal without the necessity of making the manual manipulations required by the prior art. Moreover, the presently disclosed circuit operates both in a real time sample mode where each test signal may be sampled a plurality of times, and in a sampled time mode where only a single sample may be obtained from each test signal.